Slurry shield split launching construction method for water-rich sandy gravel stratum

Abstract

The invention discloses a slurry shield split launching construction method for a water-rich sandy gravel stratum. The method comprises the following steps that A, a tunnel portal is sealed to build abin, grease is smeared on a tunnel portal brush, the tunnel portal is broken, a shield cutter head is jacked into a tunnel face, the grease is injected into a short sleeve and a muddy water bin, mudis injected into the muddy water bin, and the pressure is gradually increased to calculated incision pressure; B, shield tunneling and trolley transfer construction are conducted, a trolley is arranged before shield launching, the trolley is straightened, the tunnel portal is sealed, and the trolley is lowered into a well; and C, secondary switching of the trolley is conducted, outage and pressuremaintaining are conducted, slurry with the viscosity of 35-50s and the density of 1.1-1.3g / cm<3> is used, and permeation is conducted on the tunnel face in a large circulation mode; and slurry with the viscosity of 90-120s is injected into the muddy water bin from a central rotation standby uppermost flushing pipeline to replace the slurry in the muddy water bin, and the pressure of the muddy water bin is maintained. The method has the beneficial effects that the process is reasonable, the stability of the tunnel face of the water-rich sandy gravel stratum is guaranteed under the condition ofoutage, the high efficiency of slurry shield split launching is realized, and the cost is reduced.

Description

technical field [0001] The invention relates to a split-body starting method of shield tunneling, in particular to a split-starting construction method of mud-water shield tunneling in water-rich sand and pebble formations, and belongs to the technical field of tunnel engineering. Background technique [0002] With the large-scale construction of urban subways, large-scale river-crossing tunnel projects and water diversion projects, and with the use of urban underground space extending to deeper strata, shield construction will face complex geological conditions of large groundwater pressure, and muddy water Due to its mud-water balance process characteristics, shield tunneling is more suitable for construction under high water pressure geological conditions, which makes the mud-water shield tunneling technology more and more widely used. [0003] During the construction of urban shield tunnels, due to site reasons, the size of the shield launch shaft is generally small, whi...

AI Technical Summary

Problems solved by technology

[0005] In order to overcome the deficiency that the existing earth pressure shield is not suitable for the separate initiation construction operation of the water-rich sand and pebble formation, the present invention provides a separate initiation construction method of the mud-water shield in the water-rich sand and pebble formation

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